about summary refs log tree commit diff
path: root/third_party/lisp/alexandria/sequences.lisp
diff options
context:
space:
mode:
Diffstat (limited to 'third_party/lisp/alexandria/sequences.lisp')
-rw-r--r--third_party/lisp/alexandria/sequences.lisp555
1 files changed, 0 insertions, 555 deletions
diff --git a/third_party/lisp/alexandria/sequences.lisp b/third_party/lisp/alexandria/sequences.lisp
deleted file mode 100644
index 21464f537610..000000000000
--- a/third_party/lisp/alexandria/sequences.lisp
+++ /dev/null
@@ -1,555 +0,0 @@
-(in-package :alexandria)
-
-;; Make these inlinable by declaiming them INLINE here and some of them
-;; NOTINLINE at the end of the file. Exclude functions that have a compiler
-;; macro, because NOTINLINE is required to prevent compiler-macro expansion.
-(declaim (inline copy-sequence sequence-of-length-p))
-
-(defun sequence-of-length-p (sequence length)
-  "Return true if SEQUENCE is a sequence of length LENGTH. Signals an error if
-SEQUENCE is not a sequence. Returns FALSE for circular lists."
-  (declare (type array-index length)
-           #-lispworks (inline length)
-           (optimize speed))
-  (etypecase sequence
-    (null
-     (zerop length))
-    (cons
-     (let ((n (1- length)))
-       (unless (minusp n)
-         (let ((tail (nthcdr n sequence)))
-           (and tail
-                (null (cdr tail)))))))
-    (vector
-     (= length (length sequence)))
-    (sequence
-     (= length (length sequence)))))
-
-(defun rotate-tail-to-head (sequence n)
-  (declare (type (integer 1) n))
-  (if (listp sequence)
-      (let ((m (mod n (proper-list-length sequence))))
-        (if (null (cdr sequence))
-            sequence
-            (let* ((tail (last sequence (+ m 1)))
-                   (last (cdr tail)))
-              (setf (cdr tail) nil)
-              (nconc last sequence))))
-      (let* ((len (length sequence))
-             (m (mod n len))
-             (tail (subseq sequence (- len m))))
-        (replace sequence sequence :start1 m :start2 0)
-        (replace sequence tail)
-        sequence)))
-
-(defun rotate-head-to-tail (sequence n)
-  (declare (type (integer 1) n))
-  (if (listp sequence)
-      (let ((m (mod (1- n) (proper-list-length sequence))))
-        (if (null (cdr sequence))
-            sequence
-            (let* ((headtail (nthcdr m sequence))
-                   (tail (cdr headtail)))
-              (setf (cdr headtail) nil)
-              (nconc tail sequence))))
-      (let* ((len (length sequence))
-             (m (mod n len))
-             (head (subseq sequence 0 m)))
-        (replace sequence sequence :start1 0 :start2 m)
-        (replace sequence head :start1 (- len m))
-        sequence)))
-
-(defun rotate (sequence &optional (n 1))
-  "Returns a sequence of the same type as SEQUENCE, with the elements of
-SEQUENCE rotated by N: N elements are moved from the end of the sequence to
-the front if N is positive, and -N elements moved from the front to the end if
-N is negative. SEQUENCE must be a proper sequence. N must be an integer,
-defaulting to 1.
-
-If absolute value of N is greater then the length of the sequence, the results
-are identical to calling ROTATE with
-
-  (* (signum n) (mod n (length sequence))).
-
-Note: the original sequence may be destructively altered, and result sequence may
-share structure with it."
-  (if (plusp n)
-      (rotate-tail-to-head sequence n)
-      (if (minusp n)
-          (rotate-head-to-tail sequence (- n))
-          sequence)))
-
-(defun shuffle (sequence &key (start 0) end)
-  "Returns a random permutation of SEQUENCE bounded by START and END.
-Original sequence may be destructively modified, and (if it contains
-CONS or lists themselv) share storage with the original one.
-Signals an error if SEQUENCE is not a proper sequence."
-  (declare (type fixnum start)
-           (type (or fixnum null) end))
-  (etypecase sequence
-    (list
-     (let* ((end (or end (proper-list-length sequence)))
-            (n (- end start)))
-       (do ((tail (nthcdr start sequence) (cdr tail)))
-           ((zerop n))
-         (rotatef (car tail) (car (nthcdr (random n) tail)))
-         (decf n))))
-    (vector
-     (let ((end (or end (length sequence))))
-       (loop for i from start below end
-             do (rotatef (aref sequence i)
-                         (aref sequence (+ i (random (- end i))))))))
-    (sequence
-     (let ((end (or end (length sequence))))
-       (loop for i from (- end 1) downto start
-             do (rotatef (elt sequence i)
-                         (elt sequence (+ i (random (- end i)))))))))
-  sequence)
-
-(defun random-elt (sequence &key (start 0) end)
-  "Returns a random element from SEQUENCE bounded by START and END. Signals an
-error if the SEQUENCE is not a proper non-empty sequence, or if END and START
-are not proper bounding index designators for SEQUENCE."
-  (declare (sequence sequence) (fixnum start) (type (or fixnum null) end))
-  (let* ((size (if (listp sequence)
-                   (proper-list-length sequence)
-                   (length sequence)))
-         (end2 (or end size)))
-    (cond ((zerop size)
-           (error 'type-error
-                  :datum sequence
-                  :expected-type `(and sequence (not (satisfies emptyp)))))
-          ((not (and (<= 0 start) (< start end2) (<= end2 size)))
-           (error 'simple-type-error
-                  :datum (cons start end)
-                  :expected-type `(cons (integer 0 (,end2))
-                                        (or null (integer (,start) ,size)))
-                  :format-control "~@<~S and ~S are not valid bounding index designators for ~
-                                   a sequence of length ~S.~:@>"
-                  :format-arguments (list start end size)))
-          (t
-           (let ((index (+ start (random (- end2 start)))))
-             (elt sequence index))))))
-
-(declaim (inline remove/swapped-arguments))
-(defun remove/swapped-arguments (sequence item &rest keyword-arguments)
-  (apply #'remove item sequence keyword-arguments))
-
-(define-modify-macro removef (item &rest keyword-arguments)
-  remove/swapped-arguments
-  "Modify-macro for REMOVE. Sets place designated by the first argument to
-the result of calling REMOVE with ITEM, place, and the KEYWORD-ARGUMENTS.")
-
-(declaim (inline delete/swapped-arguments))
-(defun delete/swapped-arguments (sequence item &rest keyword-arguments)
-  (apply #'delete item sequence keyword-arguments))
-
-(define-modify-macro deletef (item &rest keyword-arguments)
-  delete/swapped-arguments
-  "Modify-macro for DELETE. Sets place designated by the first argument to
-the result of calling DELETE with ITEM, place, and the KEYWORD-ARGUMENTS.")
-
-(deftype proper-sequence ()
-  "Type designator for proper sequences, that is proper lists and sequences
-that are not lists."
-  `(or proper-list
-       (and (not list) sequence)))
-
-(eval-when (:compile-toplevel :load-toplevel :execute)
-  (when (and (find-package '#:sequence)
-             (find-symbol (string '#:emptyp) '#:sequence))
-    (pushnew 'sequence-emptyp *features*)))
-
-#-alexandria::sequence-emptyp
-(defun emptyp (sequence)
-  "Returns true if SEQUENCE is an empty sequence. Signals an error if SEQUENCE
-is not a sequence."
-  (etypecase sequence
-    (list (null sequence))
-    (sequence (zerop (length sequence)))))
-
-#+alexandria::sequence-emptyp
-(declaim (ftype (function (sequence) (values boolean &optional)) emptyp))
-#+alexandria::sequence-emptyp
-(setf (symbol-function 'emptyp) (symbol-function 'sequence:emptyp))
-#+alexandria::sequence-emptyp
-(define-compiler-macro emptyp (sequence)
-  `(sequence:emptyp ,sequence))
-
-(defun length= (&rest sequences)
-  "Takes any number of sequences or integers in any order. Returns true iff
-the length of all the sequences and the integers are equal. Hint: there's a
-compiler macro that expands into more efficient code if the first argument
-is a literal integer."
-  (declare (dynamic-extent sequences)
-           (inline sequence-of-length-p)
-           (optimize speed))
-  (unless (cdr sequences)
-    (error "You must call LENGTH= with at least two arguments"))
-  ;; There's room for optimization here: multiple list arguments could be
-  ;; traversed in parallel.
-  (let* ((first (pop sequences))
-         (current (if (integerp first)
-                      first
-                      (length first))))
-    (declare (type array-index current))
-    (dolist (el sequences)
-      (if (integerp el)
-          (unless (= el current)
-            (return-from length= nil))
-          (unless (sequence-of-length-p el current)
-            (return-from length= nil)))))
-  t)
-
-(define-compiler-macro length= (&whole form length &rest sequences)
-  (cond
-    ((zerop (length sequences))
-     form)
-    (t
-     (let ((optimizedp (integerp length)))
-       (with-unique-names (tmp current)
-         (declare (ignorable current))
-         `(locally
-              (declare (inline sequence-of-length-p))
-            (let ((,tmp)
-                  ,@(unless optimizedp
-                     `((,current ,length))))
-              ,@(unless optimizedp
-                  `((unless (integerp ,current)
-                      (setf ,current (length ,current)))))
-              (and
-               ,@(loop
-                    :for sequence :in sequences
-                    :collect `(progn
-                                (setf ,tmp ,sequence)
-                                (if (integerp ,tmp)
-                                    (= ,tmp ,(if optimizedp
-                                                 length
-                                                 current))
-                                    (sequence-of-length-p ,tmp ,(if optimizedp
-                                                                    length
-                                                                    current)))))))))))))
-
-(defun copy-sequence (type sequence)
-  "Returns a fresh sequence of TYPE, which has the same elements as
-SEQUENCE."
-  (if (typep sequence type)
-      (copy-seq sequence)
-      (coerce sequence type)))
-
-(defun first-elt (sequence)
-  "Returns the first element of SEQUENCE. Signals a type-error if SEQUENCE is
-not a sequence, or is an empty sequence."
-  ;; Can't just directly use ELT, as it is not guaranteed to signal the
-  ;; type-error.
-  (cond  ((consp sequence)
-          (car sequence))
-         ((and (typep sequence 'sequence) (not (emptyp sequence)))
-          (elt sequence 0))
-         (t
-          (error 'type-error
-                 :datum sequence
-                 :expected-type '(and sequence (not (satisfies emptyp)))))))
-
-(defun (setf first-elt) (object sequence)
-  "Sets the first element of SEQUENCE. Signals a type-error if SEQUENCE is
-not a sequence, is an empty sequence, or if OBJECT cannot be stored in SEQUENCE."
-  ;; Can't just directly use ELT, as it is not guaranteed to signal the
-  ;; type-error.
-  (cond ((consp sequence)
-         (setf (car sequence) object))
-        ((and (typep sequence 'sequence) (not (emptyp sequence)))
-         (setf (elt sequence 0) object))
-        (t
-         (error 'type-error
-                :datum sequence
-                :expected-type '(and sequence (not (satisfies emptyp)))))))
-
-(defun last-elt (sequence)
-  "Returns the last element of SEQUENCE. Signals a type-error if SEQUENCE is
-not a proper sequence, or is an empty sequence."
-  ;; Can't just directly use ELT, as it is not guaranteed to signal the
-  ;; type-error.
-  (let ((len 0))
-    (cond ((consp sequence)
-           (lastcar sequence))
-          ((and (typep sequence '(and sequence (not list))) (plusp (setf len (length sequence))))
-           (elt sequence (1- len)))
-          (t
-           (error 'type-error
-                  :datum sequence
-                  :expected-type '(and proper-sequence (not (satisfies emptyp))))))))
-
-(defun (setf last-elt) (object sequence)
-  "Sets the last element of SEQUENCE. Signals a type-error if SEQUENCE is not a proper
-sequence, is an empty sequence, or if OBJECT cannot be stored in SEQUENCE."
-  (let ((len 0))
-    (cond ((consp sequence)
-           (setf (lastcar sequence) object))
-          ((and (typep sequence '(and sequence (not list))) (plusp (setf len (length sequence))))
-           (setf (elt sequence (1- len)) object))
-          (t
-           (error 'type-error
-                  :datum sequence
-                  :expected-type '(and proper-sequence (not (satisfies emptyp))))))))
-
-(defun starts-with-subseq (prefix sequence &rest args
-                           &key
-                           (return-suffix nil return-suffix-supplied-p)
-                           &allow-other-keys)
-  "Test whether the first elements of SEQUENCE are the same (as per TEST) as the elements of PREFIX.
-
-If RETURN-SUFFIX is T the function returns, as a second value, a
-sub-sequence or displaced array pointing to the sequence after PREFIX."
-  (declare (dynamic-extent args))
-  (let ((sequence-length (length sequence))
-        (prefix-length (length prefix)))
-    (when (< sequence-length prefix-length)
-      (return-from starts-with-subseq (values nil nil)))
-    (flet ((make-suffix (start)
-             (when return-suffix
-               (cond
-                 ((not (arrayp sequence))
-                  (if start
-                      (subseq sequence start)
-                      (subseq sequence 0 0)))
-                 ((not start)
-                  (make-array 0
-                              :element-type (array-element-type sequence)
-                              :adjustable nil))
-                 (t
-                  (make-array (- sequence-length start)
-                              :element-type (array-element-type sequence)
-                              :displaced-to sequence
-                              :displaced-index-offset start
-                              :adjustable nil))))))
-      (let ((mismatch (apply #'mismatch prefix sequence
-                             (if return-suffix-supplied-p
-                                 (remove-from-plist args :return-suffix)
-                                 args))))
-        (cond
-          ((not mismatch)
-           (values t (make-suffix nil)))
-          ((= mismatch prefix-length)
-           (values t (make-suffix mismatch)))
-          (t
-           (values nil nil)))))))
-
-(defun ends-with-subseq (suffix sequence &key (test #'eql))
-  "Test whether SEQUENCE ends with SUFFIX. In other words: return true if
-the last (length SUFFIX) elements of SEQUENCE are equal to SUFFIX."
-  (let ((sequence-length (length sequence))
-        (suffix-length (length suffix)))
-    (when (< sequence-length suffix-length)
-      ;; if SEQUENCE is shorter than SUFFIX, then SEQUENCE can't end with SUFFIX.
-      (return-from ends-with-subseq nil))
-    (loop for sequence-index from (- sequence-length suffix-length) below sequence-length
-          for suffix-index from 0 below suffix-length
-          when (not (funcall test (elt sequence sequence-index) (elt suffix suffix-index)))
-          do (return-from ends-with-subseq nil)
-          finally (return t))))
-
-(defun starts-with (object sequence &key (test #'eql) (key #'identity))
-  "Returns true if SEQUENCE is a sequence whose first element is EQL to OBJECT.
-Returns NIL if the SEQUENCE is not a sequence or is an empty sequence."
-  (let ((first-elt (typecase sequence
-                     (cons (car sequence))
-                     (sequence
-                      (if (emptyp sequence)
-                          (return-from starts-with nil)
-                          (elt sequence 0)))
-                     (t
-                      (return-from starts-with nil)))))
-    (funcall test (funcall key first-elt) object)))
-
-(defun ends-with (object sequence &key (test #'eql) (key #'identity))
-  "Returns true if SEQUENCE is a sequence whose last element is EQL to OBJECT.
-Returns NIL if the SEQUENCE is not a sequence or is an empty sequence. Signals
-an error if SEQUENCE is an improper list."
-  (let ((last-elt (typecase sequence
-                    (cons
-                     (lastcar sequence)) ; signals for improper lists
-                    (sequence
-                     ;; Can't use last-elt, as that signals an error
-                     ;; for empty sequences
-                     (let ((len (length sequence)))
-                       (if (plusp len)
-                           (elt sequence (1- len))
-                           (return-from ends-with nil))))
-                    (t
-                     (return-from ends-with nil)))))
-    (funcall test (funcall key last-elt) object)))
-
-(defun map-combinations (function sequence &key (start 0) end length (copy t))
-  "Calls FUNCTION with each combination of LENGTH constructable from the
-elements of the subsequence of SEQUENCE delimited by START and END. START
-defaults to 0, END to length of SEQUENCE, and LENGTH to the length of the
-delimited subsequence. (So unless LENGTH is specified there is only a single
-combination, which has the same elements as the delimited subsequence.) If
-COPY is true (the default) each combination is freshly allocated. If COPY is
-false all combinations are EQ to each other, in which case consequences are
-unspecified if a combination is modified by FUNCTION."
-  (let* ((end (or end (length sequence)))
-         (size (- end start))
-         (length (or length size))
-         (combination (subseq sequence 0 length))
-         (function (ensure-function function)))
-    (if (= length size)
-        (funcall function combination)
-        (flet ((call ()
-                 (funcall function (if copy
-                                       (copy-seq combination)
-                                       combination))))
-          (etypecase sequence
-            ;; When dealing with lists we prefer walking back and
-            ;; forth instead of using indexes.
-            (list
-             (labels ((combine-list (c-tail o-tail)
-                        (if (not c-tail)
-                            (call)
-                            (do ((tail o-tail (cdr tail)))
-                                ((not tail))
-                              (setf (car c-tail) (car tail))
-                              (combine-list (cdr c-tail) (cdr tail))))))
-               (combine-list combination (nthcdr start sequence))))
-            (vector
-             (labels ((combine (count start)
-                        (if (zerop count)
-                            (call)
-                            (loop for i from start below end
-                                  do (let ((j (- count 1)))
-                                       (setf (aref combination j) (aref sequence i))
-                                       (combine j (+ i 1)))))))
-               (combine length start)))
-            (sequence
-             (labels ((combine (count start)
-                        (if (zerop count)
-                            (call)
-                            (loop for i from start below end
-                                  do (let ((j (- count 1)))
-                                       (setf (elt combination j) (elt sequence i))
-                                       (combine j (+ i 1)))))))
-               (combine length start)))))))
-  sequence)
-
-(defun map-permutations (function sequence &key (start 0) end length (copy t))
-  "Calls function with each permutation of LENGTH constructable
-from the subsequence of SEQUENCE delimited by START and END. START
-defaults to 0, END to length of the sequence, and LENGTH to the
-length of the delimited subsequence."
-  (let* ((end (or end (length sequence)))
-         (size (- end start))
-         (length (or length size)))
-    (labels ((permute (seq n)
-               (let ((n-1 (- n 1)))
-                 (if (zerop n-1)
-                     (funcall function (if copy
-                                           (copy-seq seq)
-                                           seq))
-                     (loop for i from 0 upto n-1
-                           do (permute seq n-1)
-                           (if (evenp n-1)
-                               (rotatef (elt seq 0) (elt seq n-1))
-                               (rotatef (elt seq i) (elt seq n-1)))))))
-             (permute-sequence (seq)
-               (permute seq length)))
-      (if (= length size)
-          ;; Things are simple if we need to just permute the
-          ;; full START-END range.
-          (permute-sequence (subseq sequence start end))
-          ;; Otherwise we need to generate all the combinations
-          ;; of LENGTH in the START-END range, and then permute
-          ;; a copy of the result: can't permute the combination
-          ;; directly, as they share structure with each other.
-          (let ((permutation (subseq sequence 0 length)))
-            (flet ((permute-combination (combination)
-                     (permute-sequence (replace permutation combination))))
-              (declare (dynamic-extent #'permute-combination))
-              (map-combinations #'permute-combination sequence
-                                :start start
-                                :end end
-                                :length length
-                                :copy nil)))))))
-
-(defun map-derangements (function sequence &key (start 0) end (copy t))
-  "Calls FUNCTION with each derangement of the subsequence of SEQUENCE denoted
-by the bounding index designators START and END. Derangement is a permutation
-of the sequence where no element remains in place. SEQUENCE is not modified,
-but individual derangements are EQ to each other. Consequences are unspecified
-if calling FUNCTION modifies either the derangement or SEQUENCE."
-  (let* ((end (or end (length sequence)))
-         (size (- end start))
-         ;; We don't really care about the elements here.
-         (derangement (subseq sequence 0 size))
-         ;; Bitvector that has 1 for elements that have been deranged.
-         (mask (make-array size :element-type 'bit :initial-element 0)))
-    (declare (dynamic-extent mask))
-    ;; ad hoc algorith
-    (labels ((derange (place n)
-               ;; Perform one recursive step in deranging the
-               ;; sequence: PLACE is index of the original sequence
-               ;; to derange to another index, and N is the number of
-               ;; indexes not yet deranged.
-               (if (zerop n)
-                   (funcall function (if copy
-                                         (copy-seq derangement)
-                                         derangement))
-                   ;; Itarate over the indexes I of the subsequence to
-                   ;; derange: if I != PLACE and I has not yet been
-                   ;; deranged by an earlier call put the element from
-                   ;; PLACE to I, mark I as deranged, and recurse,
-                   ;; finally removing the mark.
-                   (loop for i from 0 below size
-                         do
-                         (unless (or (= place (+ i start)) (not (zerop (bit mask i))))
-                           (setf (elt derangement i) (elt sequence place)
-                                 (bit mask i) 1)
-                           (derange (1+ place) (1- n))
-                           (setf (bit mask i) 0))))))
-      (derange start size)
-      sequence)))
-
-(declaim (notinline sequence-of-length-p))
-
-(defun extremum (sequence predicate &key key (start 0) end)
-  "Returns the element of SEQUENCE that would appear first if the subsequence
-bounded by START and END was sorted using PREDICATE and KEY.
-
-EXTREMUM determines the relationship between two elements of SEQUENCE by using
-the PREDICATE function. PREDICATE should return true if and only if the first
-argument is strictly less than the second one (in some appropriate sense). Two
-arguments X and Y are considered to be equal if (FUNCALL PREDICATE X Y)
-and (FUNCALL PREDICATE Y X) are both false.
-
-The arguments to the PREDICATE function are computed from elements of SEQUENCE
-using the KEY function, if supplied. If KEY is not supplied or is NIL, the
-sequence element itself is used.
-
-If SEQUENCE is empty, NIL is returned."
-  (let* ((pred-fun (ensure-function predicate))
-         (key-fun (unless (or (not key) (eq key 'identity) (eq key #'identity))
-                    (ensure-function key)))
-         (real-end (or end (length sequence))))
-    (cond ((> real-end start)
-           (if key-fun
-               (flet ((reduce-keys (a b)
-                        (if (funcall pred-fun
-                                     (funcall key-fun a)
-                                     (funcall key-fun b))
-                            a
-                            b)))
-                 (declare (dynamic-extent #'reduce-keys))
-                 (reduce #'reduce-keys sequence :start start :end real-end))
-               (flet ((reduce-elts (a b)
-                        (if (funcall pred-fun a b)
-                            a
-                            b)))
-                 (declare (dynamic-extent #'reduce-elts))
-                 (reduce #'reduce-elts sequence :start start :end real-end))))
-          ((= real-end start)
-           nil)
-          (t
-           (error "Invalid bounding indexes for sequence of length ~S: ~S ~S, ~S ~S"
-                  (length sequence)
-                  :start start
-                  :end end)))))